1. Field of Invention
The invention relates to a camera lens assembly and, in particular, to a camera lens assembly, which has an optical filter module positioned between a first lens and a second lens.
2. Related Art
With reference to FIG. 1, a conventional camera lens assembly 1 includes a barrel 11, a first lens 12, a spacer 13, a second lens 14, a blocking filter 15, a sensor 16, and a holder 17.
The barrel 11 connects to the holder 17 and includes a container 111 and a diaphragm 112. The first lens 12 is accommodated in the container 111 and is next to the diaphragm 12. The spacer 13 is accommodated in the container 111 and is next to the first lens 12. The second lens 14 is accommodated in the container 111 and is next to the spacer 13. The blocking filter 15 is set on the holder 17 and is next to the second lens 14.
The sensor 16 is disposed on a substrate 18, which is a printed circuit board or a flexible board. The holder 17 is connected to the substrate 18, wherein the holder 17 is adhered to the substrate 18.
As shown in FIG. 2, since the blocking filter 15 is next to the sensor 16, the particles of the blocking filter 15 may block the light beams passing through the diaphragm 112, the first lens 12 and second lens 14 and entering the blocking filter 15. In this case, part pixels of the sensor 16 cannot receive the light beams, which results in the blocking issue and decreased sensitivity of part pixels. Thus, the image quality is affected. Accordingly, the cleanness requirement for manufacturing the blocking filter 15 is critically concerned, so that the production yield is low and the manufacturing cost is high.
To increase production yield and to decrease manufacturing cost, those skilled people have coated a filter layer on a lens, which is however difficult. Alternatively, the blocking filter 15 is inserted in between the first lens 12 and the second lens 14 and is contacted with the spacer and lenses. However, this method causes assembling error easily. Regarding to the type of the blocking filter 15, a square blocking filter 15 has four corners to be collided with the inner of the camera lens assembly when positioning the square blocking filter 15 into the barrel 11. The collision results in several particles. To avoid the above-mentioned problem, a circular blocking filter 15 can be used. However, the production yield of the circular blocking filter 15 is much lower than that of the square blocking filter 15, so the manufacturing cost of the whole camera lens assembly is increased. In addition, when installing the blocking filter 15 at the end of the barrel 11 facing the sensor 16 and closing to the second lens 14 or at the holder 17, the cleanness requirement for the blocking filter 15 is high, which cannot solve the above problems.
It is therefore a subjective to provide a camera lens assembly, which can solve the above-mentioned problems.